var keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
function base64encode(Str) {
	//Str = escape(Str);
	var output = "";
	var chr1,
	chr2,
	chr3 = "";
	var enc1,
	enc2,
	enc3,
	enc4 = "";
	var i = 0;
	do {
		chr1 = Str.charCodeAt(i++);
		chr2 = Str.charCodeAt(i++);
		chr3 = Str.charCodeAt(i++);
		enc1 = chr1 >> 2;
		enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
		enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
		enc4 = chr3 & 63;
		if (isNaN(chr2)) {
			enc3 = enc4 = 64;
		} else if (isNaN(chr3)) {
			enc4 = 64;
		}
		output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2) + keyStr.charAt(enc3) + keyStr.charAt(enc4);
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";
	} while (i < Str.length);
	return output;
}
//解密
function base64decode(Str) {
	var output = "";
	var chr1,
	chr2,
	chr3 = "";
	var enc1,
	enc2,
	enc3,
	enc4 = "";
	var i = 0;
	var base64test = /[^A-Za-z0-9\+\/\=]/g;
	if (base64test.exec(Str)) {}
	Str = Str.replace(/[^A-Za-z0-9\+\/\=]/g, "");
	do {
		enc1 = keyStr.indexOf(Str.charAt(i++));
		enc2 = keyStr.indexOf(Str.charAt(i++));
		enc3 = keyStr.indexOf(Str.charAt(i++));
		enc4 = keyStr.indexOf(Str.charAt(i++));
		chr1 = (enc1 << 2) | (enc2 >> 4);
		chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
		chr3 = ((enc3 & 3) << 6) | enc4;
		output = output + String.fromCharCode(chr1);
		if (enc3 != 64) {
			output = output + String.fromCharCode(chr2);
		}
		if (enc4 != 64) {
			output = output + String.fromCharCode(chr3);
		}
		chr1 = chr2 = chr3 = "";
		enc1 = enc2 = enc3 = enc4 = "";
	} while (i < Str.length);
	return unescape(output);
}
